Anaerobic processes offer great advantages for the treatment of certain industrial effluents. This is why the number of wastewater treatment plants with anaerobic stages has grown rapidly in recent decades. They perfectly complement the range of aerobic processes.
A characteristic feature of anaerobic wastewater treatment is the high energy recovery from the organic freight via the biogas produced. The recycling rate is 80 to 90 per cent, only five per cent are converted into biomass. The remainder of the organic load, which is between five and 15 per cent depending on the application, is found in the anaerobic pre-treatment process and is normally removed in a downstream aerobic stage. Compared to pure aerobic biological treatment, this results in significantly lower energy consumption for aeration, lower costs for sludge treatment and sustainable energy generation from biogas. This can be used to generate electricity and heat in a combined heat and power unit (CHP). This electricity and heat can often be used to cover part of the energy requirements of production.
For wastewater with a COD concentration of more than 3,000 milligrams per litre and a COD load exceeding five tons per day, the use of anaerobic technology can drastically reduce operating costs. Typical areas of application for anaerobic processes are wastewater from the paper industry, the chemical industry and the food industry, for example in sugar factories, breweries, distilleries, in soft drink production and vegetable and fruit processing.
The energy balance of an anaerobic process varies from case to case and depends largely on the COD concentration and COD load. Further factors are the proportion of filterable substances (TSS), nitrogen and sulphate as well as the temperature and degradability of the waste water.
H+E will show you the differences between an anaerobic process and an aerobic process for your individual problem and offer you the anaerobic technology best suited to your needs. Our anaerobic waste water treatment plants have been used in the sugar and other food industries for years and ensure reliable treatment results even under fluctuating feed conditions.
The most important anaerobic technologies at a glance:
- UASB (upflow anaerobic sludge blanket)
- EGSB (expanded granular sludge bed, such as our ANAFIT®.AC)
- Contact sludge process (also see our ANAFIT®.CS reactor)
